METHOD OF PRODUCING MULTIFUNCTIONAL ADDITIVE FOR AQUEOUS DRILLING FLUIDS Russian patent published in 2024 - IPC C09K8/35 

FIELD: well drilling.

SUBSTANCE: invention relates to drilling of oil, gas and exploration wells, namely to production of additives for drilling fluids. In the method of producing a multifunctional additive for aqueous drilling fluids, a product containing methyl esters of fatty acids of vegetable oils, a fat-and-oil fraction, is first obtained by a two-step esterification reaction. At the first stage, vegetable oils soap stock is mixed—distilled fatty acids of vegetable oils, in which acid number is 185–205 mg KOH/g, with methanol at their molar ratio of 1:2, respectively, reaction is carried out for 6 hours at temperature of 130 °C and pressure of 8–9 atm, followed by distillation of water and methanol and separation of the reaction product. Reaction product with acid number in range of 148–164 mg KOH/g is sampled for the second stage of the esterification reaction. At the second step, the selected reaction product obtained at the first step is mixed with an equimolar amount of methanol and reaction is carried out for 6 hours at temperature of 130 °C and pressure of 8–9 atm with subsequent extraction of oil and fat fraction. Its average molecular weight is determined and the obtained fat-and-oil fraction with molecular weight in range of 281.7–311.3 g/mol is selected to obtain a multifunctional additive. Then, a second component of the additive is obtained—a product of re-esterification of the fat-and-oil fraction with n-butanol—by reaction of the oil and fat fraction with n-butanol at their molar ratio of 1:1.2, respectively, in the presence of a catalyst—linear alkylbenzene sulphonic acid—for 8 hours at temperature of 130 °C and atmospheric pressure. Obtained re-esterification product is selected for production of multifunctional additive with an acid number in range of 8.9–9.83 mg KOH/g and an ether number in range of 160.4–177.4 mg KOH/g. Components are mixed at the following ratio, wt.%: said oil-and-fat fraction 80–85; said re-esterification product 15–20.

EFFECT: imparting high lubricating, anti-seizure, inhibiting and anticorrosion properties to drilling fluids at reduction of effective working concentration of the additive.

1 cl, 1 dwg, 5 tbl, 3 ex